1. Field of the Invention
The present invention relates to a string securing apparatus for string instrument and, more particularly, to a string securing apparatus for string instrument that is used as a tremolo apparatus for an electric guitar.
Priority is claimed on Japanese Patent Application No. 2004-80272, filed Mar. 19, 2004, the content of which is incorporated herein by reference.
2. Description of Related Art
An electric guitar can obtain a special sound effect known as a tremolo effect, in which the musical interval is minutely increased and decreased by using a tremolo apparatus to repeatedly change the tension of a string in rapid cycles (e.g. see Japanese Unexamined Utility Model Application, First Publication No. Hei 2-119300, and Japanese Examined Utility Model Publication Nos. Sho 63-44864 and Sho 63-33242).
The tremolo apparatus includes a bridge base that is attached to the body of the guitar in a manner that it can pivot on the body of the guitar, and a plurality of bridge saddles that are arranged on the bridge base in correspondence with respective strings. One end of each string is secured to its respective bridge saddle, and the other end is wound around a peg (turning screw) provided at a head (the end of the neck) of the guitar. The most common method of securing the strings to the bridge saddles is a tightening method in which a clamp member is attached to the bridge saddle by using bolts, and securely tightens the strings to the bridge saddles. In other words, the strings are fastened in place by the bridge saddles and the clamp members (e.g. see Japanese Unexamined Patent Applications, First Publication Nos. 7-56558 and 2003-114683).
A tremolo apparatus for guitar disclosed in Japanese Unexamined Patent Application, First Publication No. 7-56558 uses a tightening manner that is similar to the conventional one described above. Saddle members are provided on a bridge plate (bridge base), blocks for clamps are fitted to the saddle members, the ends of the strings are inserted between the block for clamps and the saddle members, and bolts are used to securely tighten the block for clamps to the saddle members, thereby clamping the strings to the saddle members.
In a tremolo apparatus disclosed in the aforementioned Japanese Unexamined Patent Application, First Publication No. 2003-114683, saddle-attaching members are provided on the base plate so that they can be movably adjusted in the head-side and the tail-side directions, saddles are fitted on the saddle-attaching members so that the saddles can rotate freely upward and downward, and clamp pads are provided over the saddles. Ends of the strings are inserted between the clamp pads and the saddles, and bolts are used to tightly secure the clamp pads to the saddles, thereby securing the strings to the saddles.
Such kind of the conventional tremolo apparatus that uses the tightening method will be described in detail with reference to FIGS. 7 to 9. FIG. 7 is a plan view of the tremolo apparatus used in a guitar, FIG. 8 is a cross-sectional view taken along the line VIII-VIII of FIG. 7 in which a front face of the guitar is shown in the upper side and a rear face thereof is shown in lower side, and FIG. 9 is a perspective view of the tremolo apparatus.
In FIGS. 7 to 9, a body 1 of an electric guitar is formed with a storage recess 2 which is adapted to receive some of the constituent parts of a tremolo apparatus 3. A plurality of (six) strings are clamped along the body 1.
The tremolo apparatus 3 includes a bridge base 5, six bridge saddles 6, each of which is provided on the bridge base 5 to hold one end of each of the strings 4. Each of clamp members 7 tightly secures the one end of each of the strings 4 to the bridge saddles 6. The bridge base 5 has a tremolo arm 8 that protrudes from the treble string side (upper side in FIG. 7, it may be referred to as “treble side” hereinafter) of its front face, and is arranged on the body 1 so as to cover the storage recess 2. A pair of fulcrum sections 9 are shaped like a knife-edge, and are formed at the treble side end and bass string side (lower side in FIG. 7, it may be referred to as “bass side” hereinafter) end of a head side (leftward side in FIG. 7) of the bridge base 5. A pair of fulcrum pins 11 protrude from the front side of the body 1 to be located to correspond to the respective fulcrum sections 9. The fulcrum sections 9 are pressingly connected the fulcrum pins 11, respectively, by the spring force S of a balance spring 12 and the tension T of the strings 4 toward the head side. The balance spring 12 is located in the storage recess 2, with its head-side end interlocking with a metal fitting 13 provided in the inner wall of the storage recess 2, and its tail-side (rightward side in FIGS. 7 and 8) end connecting to the bottom end of the bridge base 5. Consequently, the bridge base 5 receives a counterclockwise (as viewed in FIG. 8) rotational momentum M1 of the tension T of the strings 4 with the fulcrum section 9 as a rotational fulcrum or a pivot, and a clockwise rotational momentum M2 (M1=M2) of the spring force S of the balance spring 12, holding the bridge base 5 in a flat state that is usually approximately horizontal.
Six saddle-attaching members 14 are secured by bolts 15 at the head-side end of the front face of the bridge base 5 in correspondence with the respective strings 4. Each of the saddle-attaching members 14 is provided with a string-length adjusting screws 24 for sliding movement toward the head-side and the tail-side directions (the stretch direction of the strings 4), as explained later. The bridge saddles 6 are connected to the saddle-attaching members 14 at the head side of the bridge saddles 6 via a rotational axis 16 so as to be able to rotate freely to the front and rear directions.
Openings 17 for storing the clamp members 7 are provided in the center of the front faces of the bridge saddles 6. Pipe sections 18 for inserting the strings 4 extend down from the center of the rear faces of the bridge saddles 6. The insides of the pipe sections 18 connect to the openings 17, and the pipe sections 18 lock with ball ends 19 that are affixed to the ends of the strings 4 by their rear or bottom faces.
The clamp members 7 are incorporated into the openings 17 in the bridge saddles 6 so that they can slide forward and backward (in the head-side and tail-side directions). A lock bolt 20 moves each the clamp member 7 forward, securely tightening the string 4 to the head-side wall of the opening 17. The lock bolts 20 are hexagonal hole-fitted bolts, being the same shape as the bolts 15, and each is fastened or loosed by an L-shaped wrench 21.
String-adjusting screws 23 that minutely adjust the tension of the respective strings 4 are fitted to the front face of the tail-side end of the bridge base 5, and the bottom or rear ends of the string-adjusting screws 23 directly contact the front faces of the lock bolts 20. When the string-adjusting screws 23 are tightened so as to press the lock bolts 20 downward, the bridge saddles 6 rotate around the rotational axis 16 in the clockwise direction (as viewed in FIG. 8). This increases the tension of the strings 4 by pulling them to the tail side. Conversely, when the string-adjusting screws 23 are loosened, the tension of the strings 4 causes the bridge saddles 6 to rotate in the counterclockwise direction, lowering the tension of the strings 4.
The string-length adjusting screws 24 are fitted to the rear face of the tail-side end of the bridge base 5, and movably adjust the saddle-attaching members 14 by moving them in the head-side and tail-side directions. Since the string-length adjusting screws 24 are provided in order to adjust the actual string length (slightly longer than the logical string length) of the strings 4 having different thicknesses. The adjusting screws 24 are rotatably attached to the tail side of the bridge base 5 and their head sides are screwed into screw holes provided in the tail side ends of the saddle-attaching members 14. Therefore, when one string-length adjusting screw 24 is rotated so as to adjust the saddle-attaching member 14 by moving it to the head-side direction, the bridge saddle 6 also moves to the same direction together with the saddle-attaching member 14, adjusting the actual string length of the string 4. Incidentally, when using the string-length adjusting screw 24 to adjust the position of the bridge saddle 6, the bolt 15 is loosened beforehand to enable the saddle-attaching member 14 to slide freely with respect to the bridge base 5.
The tremolo apparatus 3 having the above constitution obtains a special sound effect known as the tremolo effect by plucking the string 4 with a plectrum or a finger, and then using a tremolo arm 8 to repeatedly cause the pivotal movement of the bridge base 5 in rapid cycles with the fulcrum pin 11 as its pivot. This operation repeatedly changes the length of the string 4, in other words, changes the tension of the strings 4, whereby the musical interval is minutely increased and decreased.
However, since the conventional tremolo apparatuses described above secures the strings to the bridge saddles by using bolts to tighten the clamp members, the bolt must be loosened and then retightened by using a suitable tool, such as an L-shaped wrench every time a string is replaced.
In particular, since the tremolo apparatuses disclosed in the aforementioned Japanese Unexamined Patent Application, First Publications Nos. 7-56558 and 2003-114683 use the clamp member for tightening near the ends of the strings, it is necessary to cut off the ends of the strings beforehand by using pinchers or the like to remove their ring-shaped ball ends in order to prevent the ball ends from becoming obstructive.
Further, the conventional tremolo apparatus 3 shown in FIGS. 7 to 9 has a disadvantage of poor outside appearance, since the bolts 15 for securing the saddle-attaching members 14 to the bridge base 5 are exposed on the front face of the saddle-attaching members 14.